Why reverse-inheritance of namespaces would suck (part 2)

gistfile1.php

<?php

// https://bugs.php.net/bug.php?id=68485

namespace Math {
	
	class Calculator {
		
		public static function calculate($operator, $operand1, $operand2) {
			switch ($operator) {
				case "+":
					return \Math\AddOperator::add($operand1, $operand2);
				case "-":
					return \Math\AddOperator::subtract($operand1, $operand2);
				case "*":
					return \Math\MultiplyOperator::multiply($operand1, $operand2);
				case "/":
					return \Math\MultiplyOperator::divide($operand1, $operand2);
				default:
					throw new \Exception("Invalid operator '{$operator}'");
			}
		}
		
	}

	class AddOperator {
		public static function add($op1, $op2) { return $op1 + $op2; }
		public static function subtract($op1, $op2) { return $op1 - $op2; }
	}
	
	class MultiplyOperator {
		public static function multiply($op1, $op2) { return $op1 * $op2; }
		public static function divide($op1, $op2) { return $op1 / $op2; }
	}

}

namespace MoreMath {
	
	class BetterCalculator extends \Math\Calculator {
		
		public static function calculate($operator, $operand1, $operand2) {
			switch ($operator) {
				case "div":
					return \MoreMath\MoreOperators::div($operand1, $operand2);
				case ">>":
					return \MoreMath\MoreOperators::rshift($operand1, $operand2);
				case "<<":
					return \MoreMath\MoreOperators::lshift($operand1, $operand2);
				default:
					return parent::calculate($operator, $operand1, $operand2);
			}
		}
		
	}
	
	class MoreOperators {
		public static function div($op1, $op2) { return floor($op1 / $op2); }
		public static function rshift($op1, $op2) { return $op1 >> $op2; }
		public static function lshift($op1, $op2) { return $op1 << $op2; }
	}
	
}

namespace {
	
	echo MoreMath\BetterCalculator::calculate("+", 1, 2); // 3
	
}